I have a game in the making that I plan to post here. I plan to make it free as in I have no intention to make money from it, it is merely a demonstration of skill so I can show it to my future employers. Yesterday I downloaded a pack of graphics that I plan to use, but on the website that I download it from, the author wrote "This is for PERSONAL use only". I guess in theory, I can still use it and upload the game since I have no intention of making money from it, but I don't want to get into any legal trouble so I am just asking to make sure
Personally, I think you're good so long as you don't charge money- because that's what 'commercial' literally means.
If you post something on Twitter. Facebook or an online portfolio- that equally counts as 'publishing', but nobody would see that as commercial.
It's always important to consider the intentions of the owner of the assets. When people say "For personal use only" this tends to mean "Yes, you can use this, but if you make money off our work, we want some of it!"